Gotcha! If the key is twisted, the bottom is not planar. When you place the bottom of the key on a planar drill press table (or other jig), it will not lay flat, & hence the questions as to where the keytop is laying. What about setting the key on a slightly elevated position where the key forward end of the bottom rests on a rod or thin wooden riser (say 1/4" by 1/4" cross section, and 1" long) that is oriented perpendicular to key length. This gets the front of the key off the table and gets the bottom and top (at the key front) parallel to the table, and the sides perpendicular to the table. Then use movable spacers of various suitable thicknesses (perhaps 1"x1"x1/4" and other near thicknesses) to place under the rear portion of the key, moving the appropriate thickness spacer to an appropriate location such that now the keytop is parallel to the table (the rear portion of the twisted key will possibly not sit flush to the rear height adjuster). A simple sliding block with an adjustable extension on top could be used to quickly verify equal keytop height along the keytop length (similar in theory to the Jaras jig to measure backcheck and hammer checking height). Or it may be that you would want the rear support to be located at the center pin hole. That would aid in ensuring that all keytop cuts are exactly the same as they lie in the keybed. I hope you can bear with my thoughts on this. I have encountered the same problem, and am trying also to find a usable solution. Let me know. Terry Farrell Piano Tuning & Service Tampa, Florida mfarrel2@tampabay.rr.com ----- Original Message ----- From: "Paul McCloud" <smccloud@ix.netcom.com> To: <pianotech@ptg.org> Sent: Friday, March 17, 2000 12:09 AM Subject: Re: jig for Twisted-Key keytops > What I'm saying is that if the key is twisted, and you lay it flat on > your jig, the keytop may not be exactly parallel to your jig surface. > Try taking a key from a piano and lay it flat on a known flat surface. > Especially old keys from a large upright. Push down in the middle of > the key. Some keys will flex a little. Maybe it's not enough to notice > for most keys, but if there's any twist in the key, your planed surface > may not be parallel to the bottome of the key. > Paul McCloud > >
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